Hi, please : *Repair System Registry and Files

Find the Dos Prompt Right or Powershell Click and Run as Administrator then : Copy/Paste to Dos Window : DISM /Online /Cleanup-Image /RestoreHealth then hit Enter. Reboot when completed. Note : DISM goes up to Microsoft for new ones.

Download from here please and try : Current Release Firefox 59.0.1 with a Full Version Installer

• https://www.mozilla.org/firefox/all/

Please let us know if this solved your issue or if need further assistance.

Thank you very much for trying to help. I followed your instructions, but unfortunately, FF still cannot be started.

What happens when you try to start Firefox?

Do you get the crash reporter or doesn't anything happen at all?

Did you do a clean reinstall the deleted the Firefox program folder?

See also:

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware

Nothing happens when I do anything related to Firefox (e.g. start FF, safe-start FF, firefox.exe -P,...). Yes, I followed the instructions to delete the folders and reinstalled FF.

I should have stated that the small blue busy circle shows briefly when trying to start FF.

Boot the computer in Windows Safe mode with network support to see if that has effect in case security software is causing problems.

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/
• http://www.7tutorials.com/4-ways-boot-safe-mode-windows-10

Starting Windows in safe mode is one of the first things that I tried as I mentioned in my original post. I am going to wait for one or two weeks to check Firefox again and report back. I am using other browsers for now.

Hi, can try this please : Make a copy of your Profile for later :

• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data

Use Revo Uninstaller to uninstall Firefox :

• https://www.revouninstaller.com/revo_uninstaller_free_download.html

If you have a registry cleaner or use something like CCleaner (which could be the issue to begin with) Clean the registry of Firefox remains. Install again with Full Version Installer :

• https://www.mozilla.org/firefox/all/

So should work with nothing in it, no bookmarks, no add-ons nothing. If it works with clean install and new profile then can :

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Never work with original files and do not copy corrupted file to the profile which can cause the same issue.

Please let us know if this solved your issue or if need further assistance.

Thank you for the tips. I followed them. It seems Revo Uninstaller cleaned a lot of entries of the registry, and deleted many folders. I have just reinstalled FF, but the problem remains - nothing but the brief busy circles happens.

So so strange. Please use more than 1 scanner as each uses diff tech :

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware

Save your Report and google each before deleting anything as do not want to delete something you need, If need help :

• https://forums.malwarebytes.com/topic/9573-im-infected-what-do-i-do-now/

Post in only 1 forum, then wait.

Please let us know if this solved your issue or if need further assistance.

Thank you for trying to help. It is strange indeed. I had never seen this kind of problem. I did the first scan using Microsoft Safety Scanner. It scanned over 3M files on two drivers, and found three infected files, cleaned them. I rebooted the computer, and the problem remains. The scan took about 15 hours, and my computer was semi-paralyzed during the scan.

hongz said

Thank you for trying to help. It is strange indeed. I had never seen this kind of problem. I did the first scan using Microsoft Safety Scanner. It scanned over 3M files on two drivers, and found three infected files, cleaned them. I rebooted the computer, and the problem remains. The scan took about 15 hours, and my computer was semi-paralyzed during the scan.

Please to finish the job let the pros help : https://forums.malwarebytes.com/topic/9573-im-infected-what-do-i-do-now/ Is painless. Have been there done that myself. If have any cracked programs or bit torrent clients uninstall them, if have embarrassing URL's (shortcuts) on your desktop move them.

This is beyond us to help you further. You need them to help you remove anything else and the partial that did not get removed. Once you are totally clean then can help put you back together again if need further help.

I did another scan using Malwarebytes which is much quicker, and it has not made any difference. I will wait for a while before trying anything. It is not a big deal because there are a few alternatives (I am using Edge in lieu of Firefox right now).

Windows 10 had a major update yesterday (see the screenshot). I thought it was the time to try my luck again, and Firefox started flawlessly. I am not 100% sure it is the Windows 10 update that fixed the problem, but that is the only significant change to my computer since the last effort two weeks ago as far as I know.

I am unable to start Firefox again. The Windows 10 build is 17134.5 now.

I gave another shot by: 1. Uninstall Firefox. 2. Make sure Firefox folder under Program Files is deleted. 3. Make sure Firefox folders under AppData\Local\Mozilla and AppData\Roaming\Mozilla are deleted. 4. Download Firefox installer from Chrome, and run it.

Still no luck, no error messages. Just nothing showing.